In 1889 he was made an associate professor and in 1891 he carried out the first successful re-section of an upper right lung destroyed by tuberculosis.

Tuffier worked on cardio-vascular surgery alongside Alexis Carrel and carried out one of the first successful interventions for an aortic aneurysm[3] as well as the first dilation of an aortic stenosis.

[5] Théodore Tuffier married Madeleine Herbault (1867–1940) and they had two daughters, Jeanne and Gabrielle.

[1] He is also notable as the last named French owner of the Fragonard painting A Young Girl Reading.

He is remembered in modern medicine through 'Tuffier's Line', an imaginary line connecting the iliac crests, used as a landmark for the Processus spinosus L4 to identify L4/5 vertebral interspace in spinal anaesthesia and lumbar puncture.